


This Is My Brain on Steve

by Veldeia



Category: Avengers Assemble (Cartoon)
Genre: Fluff, Getting Together, Love Confessions, M/M, Science, Science Fluff
Language: English
Status: Completed
Published: 2017-09-23
Updated: 2017-09-23
Packaged: 2019-01-04 10:54:06
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,004
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12167412
Author URL: https://archiveofourown.org/users/Veldeia/pseuds/Veldeia
Summary: Steve isn't quite sure what to expect when Tony promises to send him more brain scans, but he's not going to decline an offer to learn more about the man he's fallen head over heels for.





	This Is My Brain on Steve

**Author's Note:**

> This story was written for the amazing Superhusbands Aluminum Anniversary Anthology, which you can download [here](https://stevetonystudios.tumblr.com/post/165619514047/sa3-release)!
> 
> Great big thanks to [Caz](http://archiveofourown.org/users/Lanidzac/pseuds/Lanidzac), [Muccamukk](https://archiveofourown.org/users/Muccamukk/) and [Smolsofa](https://archiveofourown.org/users/smolsofa) for beta, to [antigrav_vector](https://archiveofourown.org/users/antigrav_vector/pseuds/antigrav_vector) for the title, and also to [vorkosigan](https://archiveofourown.org/users/vorkosigan/pseuds/vorkosigan), whose story [Ad Infinitum](https://archiveofourown.org/works/9499304%22) had a line about Tony wanting to paste Steve's brain scans on his walls, which stuck with my science-loving mind and inspired this sciencey fluff.
> 
> Finally, all the kudos and love to [Caz](http://archiveofourown.org/users/Lanidzac/pseuds/Lanidzac) for doing helpful scientific illustrations for the story!

It was perfectly normal to worry for injured teammates, Steve told himself.

He would've felt the same way if it had been any of the others that they found unconscious on the battlefield: Natasha or Clint or Sam. He couldn't really imagine finding Hulk or Thor out cold. Come to think of it, if that happened, he might be even more worried, because it would take a lot to knock out either of those two.

Tony had woken up with a bit of shaking and shouting, and had insisted that he was fine and wanted to go home, but then he'd gone and asked why he was lying on the ground, obviously without any memory of having gotten there. Steve's concern had returned with a vengeance. He'd insisted that they take Tony to a SHIELD hospital, to see an actual doctor, instead of going back to the Tower where Tony would just run his own scans and consult his AI. That'd received the expected amount of protesting from Tony, but he couldn't out-stubborn Steve, not in this. Not when Steve was this worried.

It was normal to worry for teammates. It was just that Tony was prone to doing self-sacrificing stunts and then being unreasonable about things afterwards.

Steve stopped pacing, sat down on the waiting room chair, and tried to will himself to calm down. The others had retreated to the cafeteria, but he was too anxious to even consider eating. Like he would be for any of his teammates. It was perfectly normal—

He wasn't even kidding himself, was he?

He wondered if the others had already picked up on how much he liked Tony. How his feelings had grown beyond respect and friendship, past admiration, into something that was a mix of hope, frustration and yearning.

Tony hadn't noticed, Steve was sure of it. Tony would've done or said something otherwise. He was always very vocal when he wanted something. Steve wasn't exactly Tony's type, anyway. Tony's type would be more tech-savvy, smarter, and probably female. When it came to Steve, half of the time Tony was really nice, the other half he was making fun of him, as they did in the team. The occasional fond quips weren't any different from the way he interacted with any of the others. Good friends. Steve liked being friends, but still, as much as he knew it wouldn't happen, he couldn't help wishing they could be more.

The sound of a door opening startled Steve out of his contemplation. He sat up straight, struggling to keep his face neutral. Somehow, he felt like he'd been caught in the act. It didn't help at all that the person who appeared at the doorway was the very subject of Steve's thoughts.

Tony leaned on the doorframe, dressed in his undersuit. "Cap! Just the man I need!" he exclaimed.

"Should you be up already?" Steve returned, eyeing him suspiciously. Was that smile a bit strained? Did he seem a little pale? At least there were no visible bruises on his face, that was good.

"Yes. I'm barely injured." Tony stepped forwards, keeping one hand on the doorframe, then let go of it to cross the floor to the chair next to Steve's in slightly unsteady steps. That certainly didn't lend much credibility to his words. He flopped down on the chair heavily.

Steve crossed his arms. "Are they letting you go, or did you just run away?"

"They are, actually, as long as someone promises to look after me," Tony said, making a distasteful face. "Which is just them being overly cautious. I'm fine."

"Are you, really?"

"Yes! Honestly! I promise. See for yourself!" Tony poked at a StarkPad he'd been carrying in one hand, then held it out towards Steve.

Steve accepted the tablet, frowning at it. On it was a single image that took up most of the screen: a gray and black oval, filled with a complex pattern of different shades of gray that was mirrored from left to right. The borders of the oval where white against a black background. It took him a while to understand what he was looking at. 

"This is your brain?" he asked.

"Yup. The most brilliant one you'll ever rest eyes on," Tony said. Modest as always. "You can swipe to the sides to get different views. Bottom line is, it's perfectly intact."

Steve tried switching the image as Tony had said, and was rewarded with a series of similar images, with varying patterns of black and gray. He had no idea how to tell whether the scans he was looking at were normal, but he still found them fascinating. Modern medical technology was one of the things that impressed him the most about this future he was now living in. It was amazing that they could just take a picture of someone's brain like this. Of course, like Tony had said, this wasn't just any brain, either. Steve wondered if it looked somehow different from most because it was where Tony's genius mind lived.

"No bruising, no bleeding. All fine," Tony went on. "Just got a bit of a jolt, that's all."

Steve glared at him. "A bit of a jolt. So, you're saying that you do have a concussion."

"Just a mild one," Tony said, shrugging dismissively. "I've had far worse. They said rest until I feel normal, and have someone keep an eye on me. I was hoping you'd volunteer."

"You can count on it," Steve promised.

"Great. Let's go home, then. This place gives me the creeps." Tony stood up again, holding out a hand for his StarkPad.

Steve was almost reluctant to give the device away; he was still captivated by the images. "This was actually really interesting," he commented as he offered it back to Tony.

"Really?" Tony accepted the tablet and gave him a lopsided grin, looking pleased. "Well, if you liked that, I've got plenty more where it came from."

"Sure," Steve said, on reflex.

As soon the word was out he realized that he had no idea what he'd actually agreed to. Tony's suggestion had sounded almost flirty, hadn't it? Or was it just Tony being himself and Steve overinterpreting it? And if it was flirty, what kinds of images would Tony send him next? The thought made him excited and uneasy at the same time. He hoped he wasn't blushing.

He would happily look at any and all parts of Tony, but then again, he didn't want things to become awkward between them. Had that been a mistake? He could still take the words back. Maybe he should—but he was also genuinely curious to find out where this would lead.

Before he'd come to any conclusion as to whether he'd just done something stupid or taken the first step towards something that he really wanted, the rest of the Avengers filed into the waiting room, surrounding them, and the moment was lost.

*****

Steve kept expecting Tony to bring up the topic on the following days, but he didn't, even though they spent a lot of time together. He wondered if Tony had forgotten about the whole thing, and should he maybe ask him about it, to make sure Tony still remembered that conversation. After all, memory issues were on the list of potential late symptoms to watch out for that Steve have received from the SHIELD doctor. In the end, he decided to leave it be. He really hadn't spotted anything else to suggest that Tony had trouble remembering things. As for the other items on the list, when questioned sternly, Tony had admitted to having headaches and feeling a little fuzzy every now and then, but that was to be expected.

Steve focused on doing his best to make sure Tony took it easy for at least a few days. That was a nearly full-time job, consisting of repeatedly hauling Tony out of his workshop and organizing plenty of movie nights and board game evenings and other team activities to distract him from his work. Luckily, the whole team was in on this.

Steve would've been lying if he'd said he didn't enjoy spending all this time with Tony, even if he hated that it was because Tony had gotten hurt on a mission.

Four days into the "full week of light duty, at minimum" that the SHIELD doctor had recommended for Tony, there was a call to assemble. Steve expected it to require all his determination to persuade Tony to sit out the mission, but Tony's objections seemed somewhat uninspired, and he gave in easily.

"Go fight the bad guys. Make me proud," Tony told them on the way out. "I'll manage just fine on my own for a few hours."

Come to think of it, when he said it like that, Steve guessed Tony might be fed up with having to spend almost every waking hour in the company of his teammates, not having as much time to himself as he usually did.

The next morning, when Steve was having breakfast after his run, his phone told him he had a message from Tony. He opened it, curious, and found out that Tony hadn't forgotten about their conversation after all.

_I promised I'd have more_ , it simply said. 

There were two pictures attached. They were some kind of brain scans, that much was obvious, but they seemed far more sophisticated than the ones Steve had seen earlier. Instead of two-dimensional cross sections, they were three-dimensional models. When he poked at the touch screen, he found out that he could turn the images around to see them from all angles. They were mostly gray, but with some areas highlighted in bright colors, following a gradient from yellow to red. The main difference between the two scans, as far as Steve could see, was that the second one was significantly more colorful than the first, whatever that meant.

Steve's first reaction was to wonder if this was what Tony had been up to the previous night while the rest of the team had been out on that mission. The second was, what was Tony trying to tell him with this? There were no other words in the message, no explanation at all as to what these two scans represented and why they were so different. Should he be concerned?

"JARVIS, is Tony awake yet?" Steve asked.

"Yes, Captain," the AI replied. "He's in the laboratory."

His half-finished coffee and untouched oatmeal forgotten, Steve got up and headed towards Tony's lab.

As Steve entered the large workspace, Tony swiveled around in his desk chair to face him with a wide, carefree smile. "Morning, Cap! What can I do for you?"

"Do you have to ask?" Steve returned. It came out sounding quite grumpy. "Obviously, it's about that message you sent."

"What about it?" Tony asked airily.

Why did Tony always have to be like this? His casual demeanor did nothing to reassure Steve, because he knew Tony might easily keep up such a front even if something was seriously wrong. Sure, the message he'd sent would be an odd way of telling Steve about health issues, but he had to check, anyway. "Are you all right?"

Tony rolled his eyes. "We've been through this a hundred times. Yes. Perfectly fine. Starting to grow bored with the house arrest. I'm hoping you'll let me out to play again soon."

Steve relaxed, letting his tightly crossed arms fall to his sides. "So, those scans, then?" he asked, ignoring the rest of Tony's comment. "Why do they look so different from one another? What's going on with them?"

"Where's the fun in me just telling you that?" Tony evaded him.

"What's the point of sending them to me if you're not going to explain them?" Steve returned.

"Consider it a puzzle," Tony said cheerfully. "You said you were interested, this is your chance to learn more about the miracles of modern technology, and me." He tapped at his temple, and winked.

That seemed so openly flirty, Steve didn't know what to do with it. Of course, this was Tony. He was like this. It didn't mean anything.

Steve harrumphed to cover how flustered he felt. "It might be easier to learn if someone taught me," he parried, trying his best to sound blasé. Not half bad, as replies went, he thought.

"Maybe later. I'm a bit busy now," Tony said. "You can always ask JARVIS for help."

That sounded far too simple. "Is he going to actually explain those scans to me?" Steve asked suspiciously.

"Nah, but he'll point you in the right direction," Tony said, just as Steve had expected.

More confused than he'd been to begin with, Steve retreated to his room to start looking into this puzzle Tony had laid out for him. He sat down at his desk and switched on the large screen that he rarely used to put up the scans on it. They stared back at him just as inexplicable as before. Never mind how fascinating—and slightly disturbing—it was that these models of Tony's brain seemed so detailed, it was as if someone had just stepped inside his head to draw them, Steve was more frustrated than curious.

What kind of a game was Tony playing at? Had he figured out Steve had feelings for him? Was he making fun of Steve? Practical jokes were generally Clint's territory, but right now, Steve had no idea what was going through Tony's head, even if he was very literally looking at its contents.

"Okay. JARVIS, I suppose you can't just tell me what these scans are and what they mean," Steve asked.

Rhetorical as the question was, JARVIS answered, as he tended to do. "Not as such, no. I can, however, tell you that what you're looking at are measurements performed using proprietary Stark magnetoencephalographic imaging, overlaid on 3D reconstructions of computed tomography scans."

Well, that was a mouthful. Steve had no idea what it meant, but contrary to popular belief and continued jokes from his teammates, he had no issues dealing with all sorts of modern technology. Tony clearly expected him to be able to understand this. He'd be damned if he didn't at least try.

"Right. I guess that's a start," Steve said. "Tell me more about this tech."

A few hours later, Steve's rumbling stomach reminded him that he had pretty much skipped breakfast, and it was time for lunch. He'd learned a lot about various types of brain imaging, all of which he found very impressive, but he wasn't much closer to guessing what was up with these particular scans.

The colors in the scans, he'd found out, corresponded to changes in magnetic fields, which meant neuronal electrical activity, so the second scan seemed to have more of that than the first. That wasn't very specific. Had Tony been thinking more actively when he'd done the second scan? Or was he maybe asleep in the first one? Even if Steve knew there was more brain activity happening in one picture than the other, that didn't really tell him anything. To answer that, he'd probably need to know more about the regions of the brain that were particularly active, and that turned out to be very complicated. It might be that he'd just need to wait for more hints to solve this.

He sighed and put away the images. He needed food.

*****

Steve went back to the images several times over the following days, but he didn't really get anywhere. He tried to talk to Tony again, mentioning that he'd figured out the basics of the scans. Tony commended him for his effort, but just smiled enigmatically when Steve asked for further hints.

Eventually, he did get a new hint, or rather, another message. He received it on the morning of the day when Tony was officially back on the active duty roster. It was probably not a coincidence that he had taken the opportunity to go on a test flight in his newly repaired suit so he wasn't around for more questions when Steve opened the message.

_These go together with the previous ones_ , Tony had typed. Just that and nothing else.

Steve looked at the first of the two attached files, and frowned. This was something completely different from what he'd seen so far. It wasn't actually an image, but some kind of a very complicated line graph, with nine rows of fine, sawtooth-like lines on a white background. Steve's first association was to heart monitor screens that he'd seen when one of his teammates had ended up badly injured and in the hospital, but that didn't seem quite right. He thought the lines should've showed clearer patterns instead of such messy squiggles.

The second image was similar to the first, except that the lines looked somewhat different, with smaller peaks that were closer to one another.

He walked over to his desk to inspect the two graphs side by side on the screen. "JARVIS? Can you tell me what I'm looking at?" he tried.

"Electroencephalograms, Captain. EEGs, for short," JARVIS replied.

That didn't mean much to Steve, though he did think he'd heard the term before. "That's another kind of brain test, right?"

"Indeed it is," JARVIS confirmed. "A considerably simpler one than the scans you saw earlier, measuring electrical activity with electrodes placed on the scalp."

Steve sighed. "But what does it mean?"

"That I sincerely cannot tell you," JARVIS said unhelpfully.

The information Steve found on the internet wasn't all that helpful, either. Even though he made some headway into interpreting the complicated graphs, which one text described as perplexing even to professionals, he was still no closer to understanding what Tony was getting at.

Steve caught Tony as soon as he was back from his flight. The way he was lounging on the common room sofa, still in that sleek undersuit which Steve always had to struggle not to stare at, he very much looked like he'd been expecting Steve.

"Hi, Tony," Steve greeted him. "Nice flight?"

"Awesome! I missed that so much, you've no idea. Not many things I like more than flying," Tony said, flashing him a wide grin.

"Glad to hear that." Steve considered sitting down next to Tony, but decided against it, even though standing up made him feel like an interrogator. "Anyway. You know why I'm here."

"Probably." Tony shrugged. "I don't expect you'll want to hear about the improved maneuvering capabilities that I achieved by fine-tuning the back flaps on my armor—this was the perfect opportunity since those got a bit bent in that battle, and—"

"Tony," Steve interrupted. "The EEGs. I know what's on them. One has mostly alpha waves, so that's a relaxed state. The other is beta waves, in the mid to high range, which is active thinking, even anxiety or stress. Since you already said these match the functional scans, one with less activity and the other with more, this doesn't really tell me anything that I hadn't guessed based on your first message."

Tony rubbed at his goatee in a mock thoughtful expression. "Huh. You're right. But they're pretty cool, aren't they? So much simpler than the high-tech scans, yet still so useful. You said you found this stuff interesting—I bet you've learned plenty of new things!"

"Well, they are, and I have," Steve admitted. He hadn't stopped to consider that, too immersed in trying to solve the puzzle. He did know a lot more about modern medical technology now than he had a week ago. Still, that didn't do away with his frustration. "Be that as it may, no matter how much I stare at these things, I still can't read your mind. If you're trying to tell me something, why don't you just say it?"

"All in good time! I promise the next one will be more informative." Tony's smug look shifted a little, his eyes growing serious. "That is, if you still want to see it."

Exasperated as he was, Steve wasn't about to quit halfway through. "Of course I do."

"Good, good." Tony's lips quirked into a smile again.

Steve spent the rest of the day awfully preoccupied, his mind going over the conversation and those mysterious messages again and again, and checking his phone for new messages. No luck there.

He knew what he wanted it all to mean: that Tony was thinking about him, because he was as interested in Steve as Steve was in him, and that this was his convoluted, roundabout way of telling it. It seemed like a possible explanation for those scans and graphs, but would Tony really do all this just to… to woo Steve?

That must be wishful thinking on Steve's part. Tony liked puzzles and games. Maybe this was just a bit of fun for him. Steve wasn't going to get his hopes up.

*****

_These aren't related to the previous measurements_ , Tony's next message said. There was also another line of text: _I've got one last thing I'd like to share after this. Let me know if you want to see it._

At first glance, Steve definitely wouldn't have called this message "more informative" than those previous ones. More like the opposite. Tony had sent him more graphs, but these were even simpler than the EEGs. Specifically, JARVIS informed him, they were called box and whisker plots, in which the boxes and whiskers summarized several different statistical metrics, from median value to quartiles.

There were seven plots in total, each with two boxes that were labeled "Before" and "After" below the horizontal axis. On the vertical axis were numbers and names that Steve thought must be biological chemicals. Most of them seemed to have higher values "After". A few of the names he had heard before—he did know testosterone and estrogen, and norepinephrine sounded vaguely familiar—but the rest of them—dopamine, oxytocin, serotonin and vasopressin—didn't mean anything to him.

"Before and after what, though," Steve mumbled. If they had nothing to do with the earlier messages, could they maybe refer to that concussion that had started this little game of Tony's?

"I'm not at liberty to say," JARVIS replied, as usual.

Steve sighed. "Yeah, I know."

The logical starting point, and really the only thing he could do, was to look up each chemical and try to figure out what they were.

He found out that all the chemicals were hormones, and that like he'd thought, norepinephrine was related to the fight-or-flight response—he'd actually been thinking of epinephrine, which was a similar chemical. Dopamine, he read, was involved in a variety of things ranging from addiction to controlling movements.

That was as far as he got before a call to Assemble interrupted him.

All through the mission, Steve had the nagging feeling that Tony was staring at him. That didn't make any sense; Tony was wearing his armor, and he wouldn't need to physically look at Steve to know where he was or what he was up to. Still, he actually caught Iron Man's masked face turning towards him several times.

He wondered if Tony might be biting his tongue to keep himself from asking Steve whether he had figured out those plots yet. Tony had seemed serious and maybe a little nervous when he'd asked if Steve wanted to continue working on this puzzle.

Steve decided two could play at this game. He wasn't going to say anything or ask about this latest message until he had reached some kind of a conclusion. He focused his energy on taking out Hydra goons. It was a good way to get rid of some of his pent-up frustration.

They ended up spending the entire day on the mission, the cleanup, and the debriefing after it, because these particular Hydra goons had been involved in sabotaging a SHIELD facility. With the team seated together around a table and Tony's face visible, his visor up, it was even more obvious he was trying to sneakily catch a glimpse of Steve every now and then.

Steve was determined to keep his resolve and not talk to Tony at all. Maybe that was slightly mean of him, but Tony had been teasing him for several weeks. He was growing very curious, though. What could those completely innocuous, drab-looking plots possibly contain that would make Tony so antsy?

It seemed to take forever until they were finally done and could return to the Tower. By then, the hour was so late that there was no discussion of a shared post-mission dinner; everyone grabbed whatever snacks they could find and disappeared into their rooms.

"Steve—" Tony called out after him, as Steve was heading out of the kitchen with a small tower of sandwiches and a carton of milk.

Steve stopped and turned to face him. "Whatever it is, I'm sure it can wait till the morning."

"Look, I just—I want to apologize," Tony said, staring at some point over Steve's shoulder and looking visibly uneasy. "It was presumptuous of me to assume things, I feel like an ass, is there any chance we could just forget about the whole thing?"

Tony must think Steve had already figured out those mystery plots and was avoiding him because of whatever they meant. Steve felt like kicking himself. He'd wanted to get back at Tony, but he'd not wanted to be this cruel.

"Tony. I haven't solved your puzzle yet," Steve told him. "I didn't have enough time. Got interrupted by Hydra."

"Oh," Tony breathed, then bit his lip. "Oh. Okay. This is also awkward. Never mind then. Can we maybe pretend I never said anything?"

"I didn't hear a word," Steve said, trying to sound encouraging. "Good night, Tony."

"Good. Night," Tony mumbled.

Steve didn't think he'd ever seen Tony this tongue-tied.

He made his exit, his mind buzzing. He couldn't think of many things that would make Tony react like he had. Really, could there be any other explanation than the one Steve was hoping for? But if he was right about this, how were the plots supposed to tell him that?

Determined to get to the bottom of this for once and for all, Steve sat down at his desk once more and went back to the internet searches.

The next hormone on the list was oxytocin. He looked it up and smirked at the screen. It was the sort of thing he'd been hoping for: among the many functions of the molecule were things like romantic attachment, bonding and reproduction. Encouraged by this, he quickly skimmed through the basics of the rest of the list, but they were nothing as obvious. Sure, serotonin had to do with happiness and moods in general, but also appetite and memory and a dozen other things, and vasopressin seemed mainly related to regulating blood pressure and water levels in the body.

Steve sighed. It turned into a yawn. It was getting very late and he was tired, but he'd be damned if he couldn't figure this out. Tony clearly thought he could do it, so it couldn't be impossibly complicated—although what with also trusting Steve to learn how to interpret brain scans, Tony's expectations could be quite high.

Seven hormones, each doing a wide variety of things, some of them obviously involved in social behavior and relationships, others not so much. Was he going about this the wrong way?

Maybe it wasn't they did. Maybe this was some kind of a coded message? He typed the names of the molecules on top of one another, looking at the first letters. He got "ton" and "sev" out of those, and a leftover "d". Or maybe "stev", "no" and "d"? Nah, that couldn't possibly be it. Tony wouldn't go through all this trouble to send him a badly made obscure word puzzle.

On a whim, Steve entered the entire list of hormones into a search engine at once, not expecting that to make him any wiser.

The results appeared in the blink of an eye, as always, and—bingo!

The entire first page of results was about love.

_Biological basis of love_ , read the first title on the list. The second one was _The science behind lust, attraction, and companionship_ , followed by _Science of Love_ and _Love & Chemistry_.

That couldn't be a coincidence. It was exactly the sort of thing Steve had hoped he'd find.

Tony liked him. There could be no other explanation. Especially not when considering how flustered Tony had seemed about the whole thing. "Before" and "After" must refer to before they met, or before Tony developed those feelings.

In the message, Tony had asked if Steve wanted to see one last thing. He should let Tony know he did. He was both excited and nervous about that. 

He glanced at the time: well past midnight. Maybe he should wait for the morning. Then again, Tony rarely went to bed at a reasonable hour.

Steve generally favored face-to-face conversations over electronic messaging of any kind. Even a voice call would be preferable, but in this case, it felt closer to the spirit of the challenge to respond to Tony's message electronically.

He spent an inordinate amount of time trying to word his reply, going from long confessions of how he felt and how he'd been sure Tony would never reciprocate to just one sentence asking for that last thing. Finally, he settled on a short, simple and playful, _I think I've figured it out. Very interesting. Please tell me more._

Steve sent the message and retreated to his bed, placing his phone on the nightstand. He flopped on top of the sheets, still fully clothed. If he knew Tony at all, the answer would be prompt. He was also fairly sure he wouldn't be able to sleep as he waited for it. In the war, he'd developed the skill to fall asleep the moment he closed his eyes, and he still had that, but this was different.

His nervous brain kept questioning whether there was still some chance that he might've misunderstood the whole mystery. Maybe it was an accident that all these hormones were related to love and the message Tony had wanted him to decipher had been something else entirely. Something less romantic. Steve couldn't come up with anything that'd fit, but that might just be because he lacked imagination. 

He also worried about what would happen if he'd been right. What kind of a thing would Tony send him next? And what would happen after that? He hadn't really thought this through at all. What would he say to Tony? What would Tony say to him? Would there be kissing? Would they start dating? Should they tell the rest of the team? There would be so much teasing if they did, they might never live it down.

A bleep from his phone pulled him out of the anxious thought spiral.

It was another message from Tony. Of course it was; who else would text him this time of the night?

His hands shaking, Steve opened it.

_In case it wasn't clear yet, this is yours. If you'll have it._

_(I'll be in my lab if you want to talk.)_

There was only one file attached to this message: another scan of some kind, but not of Tony's brain. If not for the animation, Steve might not have made sense of the black, white and gray blob on the smallish mobile phone screen, but the rhythmic movement made it very obvious. It was a heart.

Tony's heart.

Steve's, if he'd have it.

Steve stared at the image, the hugest grin on his face.

Of all the scans and measurements Tony could've picked, this had to be the sappiest. Steve wouldn't have taken Tony for such a romantic. Then again, what with the arc reactor in his chest, it was probably the type of scan he'd had done more often than any other.

The part of Steve's mind that remembered everything he'd read about medical imaging tried to run on a tangent, wondering what type of a scan this was and how Tony had managed to make it so clear, without any interference from the arc reactor, which wasn't visible in the image, and if maybe JARVIS would tell him—but he didn't _really_ care about that right now. There were more important things to deal with.

*****

The elevator ride to Tony's lab seemed to take forever. Steve spent most of it staring at his reflection. His cheeks looked pink. He was definitely blushing. He supposed Tony wouldn't mind.

He almost walked into Tony as he entered the lab, because Tony was standing right next to the door. Knowing him, he'd probably asked JARVIS to keep track of where Steve was so he could be prepared.

Tony greeted Steve with a wide but slightly nervous-looking smile. "Hi. Fancy seeing you here this time of the night."

"Hi," Steve returned. What should he say now? He'd thought about this so much and he still had no idea. He bet his brain scans would light up in colors as bright as an expressionist painting. "Uh. So," Steve stammered.

"So, you've figured me out," Tony said, appearing a little more on top of the situation than Steve. "But I'm at a disadvantage here. I really have no idea about you. I mean, you're here, that's clearly a good sign, but other than that—"

Actions always spoke louder than words, right? Steve stepped up to Tony, into his personal space, and placed one hand on his back.

"Okay, this is even better. This is very promising," Tony said, leaning towards Steve, so close that their lips nearly touched and Steve could feel his breath against his skin as he spoke.

Steve waited for Tony to move even closer, but he didn't, letting Steve take the initiative. Almost as if he still couldn't quite believe that Steve wanted this. Steve needed to show Tony that he really, really did.

He pressed his lips against Tony's, like he'd wanted to for so long. He hadn't thought it would ever happen. He'd wondered about how it might feel. Surreal, it turned out, was the word he'd use to describe it. The day had been so long and eventful and the hour was so late—or rather, so early—that it made the scene feel distinctly dream-like, a little fuzzy around the edges. Tony's beard was prickly, like Steve had thought it might be, his lips warm and eager against Steve's.

As he kissed Steve back, Tony hooked one foot behind Steve's leg and wrapped both arms around him, pulling them even closer to one another. Close enough that Steve felt the arc reactor casing against his chest, right next to his own racing heart. That reminded him of that last scan Tony had sent. Ridiculous and romantic.

Suddenly, Steve realized what he should've said right away.

He backed away slightly, letting his lips detach from Tony's, fixing Tony's eyes with his instead. "The answer's yes, by the way."

"Yes, to—" Tony said. He was frowning, obviously disappointed they weren't kissing anymore, the touch of his hands on Steve's back feather-light and hesitant. It didn't take long for him to catch up, though, and then, his face lit up as he realized what Steve must be referring to. "Oh!" he exclaimed.

"And mine is yours, too. If you didn't figure that out yet," Steve added.

"That was my working hypothesis all along," Tony said, his smile more relaxed than before, his eyes twinkling. "I'm glad it's now been empirically proven."

"Me too," Steve agreed. "And I've got to say, as interesting as all that modern medical science is, nothing will ever beat an old-fashioned hands-on approach."

"Can't disagree with that. Actually, I might want to run a few more of these experiments," Tony said, hugging Steve closer to him again, and going for another kiss.


End file.
